Method for spatially confining vibrational energy

Abstract

A method for isolating vibrations from a source on a structure includes modeling the structure as a beam having a portion for isolation. A sensor is positioned proximate to the source, and at least one actuator is positioned on the structure between the source and the portion for isolation. A controller receives signals from the sensor and calculates vibrational inputs for each actuator that will isolate the structure portion. Driving signals are provided to each actuator by the controller in response to the calculated vibrational inputs, and each actuator is vibrated accordingly, isolating the structure portion from the source. This method can be implemented in multiple configurations to isolate the structure portion.

What is claimed is: 
     
       1. A method for isolating vibrations from a source on a structure:
 modeling the structure as a beam having a portion for isolation by dividing the structure into nodes, and developing a pentadiagonal matrix representing displacements of the structure at each node responsive to vibrational loads provided at particular nodes of the structure; 
 positioning a sensor proximate to the source; 
 positioning at least one actuator on the structure between the source and the portion for isolation; 
 receiving signals from the sensor at a controller; 
 calculating vibrational inputs for each at least one actuator that will result in no vibration in the portion for isolation utilizing received signals from the sensor and the structure model; 
 providing driving signals responsive to the calculated vibrational inputs from the controller to each at least one actuator; and 
 vibrating each at least one actuator in response to the first and second driving signals. 
 
     
     
       2. The method of  claim 1  wherein the step of calculating vibrational inputs comprises:
 representing vibrations from the source as vibrations at a particular node; 
 representing vibrations from said at least one actuator as vibrations at a particular node; and 
 utilizing the calculated pentadiagonal matrix to calculate vibrational inputs for each at least one actuator. 
 
     
     
       3. The method of  claim 1  wherein the step of modeling the structure as a beam models the structure as a beam having a first end and a second end where each end is simply supported. 
     
     
       4. The method of  claim 1  wherein the step of modeling the structure as a beam models the structure as a beam having at least one cantilevered end. 
     
     
       5. The method of  claim 1  wherein the source includes multiple sources and the sensor includes multiple sensors with one sensor positioned at each of the multiple sources. 
     
     
       6. The method of  claim 1  further comprising the step of estimating a source vibration wavelength, and wherein said step of positioning at least one actuator includes positioning at least one actuator such that the actuator has a contact area with the structure that has a width of about a hundredth of the estimated source vibration wavelength. 
     
     
       7. The method of  claim 1  wherein the source generates vibrations having multiple frequencies, and the at least one actuator vibrates with multiple frequencies. 
     
     
       8. A method for isolating vibrations from a source on a structure:
 modeling the structure as a beam having a portion for isolation by dividing the structure into nodes, and developing a pentadiagonal matrix representing displacements of the structure at each node responsive to vibrational loads provided at particular nodes of the structure; 
 positioning a sensor proximate to the source; 
 positioning at least one actuator on the structure between the source and the portion for isolation; 
 receiving signals from the sensor at a controller; 
 calculating vibrational inputs for each at least one actuator that will result in no vibration in the portion for isolation utilizing received signals from the sensor and the structure model by representing vibrations from the source as vibrations at a particular node, by representing vibrations from said at least one actuator as vibrations at a particular node, and utilizing the calculated pentadiagonal matrix to calculate vibrational inputs for each at least one actuator; 
 providing driving signals responsive to the calculated vibrational inputs from the controller to each at least one actuator; and 
 vibrating each at least one actuator in response to the first and second driving signals. 
 
     
     
       9. The method of  claim 8  wherein the step of modeling the structure as a beam models the structure as a beam having a first end and a second end where each end is simply supported. 
     
     
       10. The method of  claim 8  wherein the step of modeling the structure as a beam models the structure as a beam having at least one cantilevered end. 
     
     
       11. The method of  claim 8  wherein the source includes multiple sources and the sensor includes multiple sensors with one sensor positioned at each of the multiple sources. 
     
     
       12. The method of  claim 8  further comprising the step of estimating a source vibration wavelength, and wherein said step of positioning at least one actuator includes positioning at least one actuator such that the actuator has a contact area with the structure that has a width of about a hundredth of the estimated source vibration wavelength. 
     
     
       13. The method of  claim 8  wherein the source generates vibrations having multiple frequencies, and the at least one actuator vibrates with multiple frequencies.